I currently have an Albizia julibrissin 'Summer Chocolate' growing in a pot on my patio. It grew well last year, and burst into life this year. Now however, I'm noticing many of the new side shoots have fallen off and the leaves are curling and falling. I don't see any discolouration, insects, or cracked stem/bark. I don't believe it's too dry between waterings, if anything too wet maybe? Does anyone know what might be wrong? I do also have a campanula planted in the bottom of the pot. Any insights would be much appreciated!